Megalodon was a warm-blooded killer, but that may have doomed it to extinction

Researchers who examined the megalodon's petrified teeth came to the conclusion that the enormous extinct type of shark was warm-blooded.

According to recent study, the extinct megalodon shark, which roamed the waters between 23 million and 3.6 million years ago, was probably warm-blooded and had a body temperature that was considerably greater than that of sharks today.

The megalodon (Otodus megalodon), whose species name means "big tooth," was studied by a group of international experts who discovered the discovery while examining its petrified teeth. According to a research published Monday (June 26) in the journal Proceedings of the National Academy of Sciences, these giant carnivores frequently grew to be around 50 feet (15 meters) long, equivalent in length to tractor-trailers.

Megalodon is categorized in the current research as being "regionally endothermic," which means that it can retain its body heat even when its external environment is significantly cooler, like many shark species, including great whites (Carcharodon carcharias).

The proportions of various isotopes, or versions of elements, in preserved megalodon teeth were utilized by the researchers to determine the gigantic shark's body temperature for the study.

According to study co-author Kenshu Shimada, a professor of paleobiology in the College of Science and Health at DePaul University in Chicago, "the degree to which these isotopes have bonded or 'clumped' together can be extrapolated from the temperature at which the mineral formed, including biologically mineralized hard tissues like teeth." "The warm-bloodedness of dinosaurs was previously investigated using the geochemical method utilized. With the help of their strong, well-mineralized anatomical parts like teeth, the current study shows that marine animals like sharks can also use the technique.

According to the study, current sharks with regional endothermy have an average body temperature between 72 and 80 degrees Fahrenheit (22 to 26.6 degrees Celsius), but the megalodon's average body temperature was determined to be roughly 80 degrees Fahrenheit (27 degrees Celsius).

The megalodon would have benefited greatly from its higher body temperature.

"Warm-bloodedness is advantageous because it allows an animal to have a more active lifestyle, such as being able to sustain long-distance or fast swimming," said Shimada. Today's warm-blooded sharks, such makos and great whites, not only have faster swimming speeds than their cold-blooded relatives, but their high metabolic heat also makes it easier to digest food.

Warm-bloodedness did have certain disadvantages, too, and it's possible that it contributed to the extinction of the megalodon.

"The timing of Megalodon's disappearance in the fossil record corresponds to the climatic cooling of the Earth," stated Shimada. "Megalodon's warm blood may have really given it a 'extra edge' to be able to live in cooler seas. The fact that the species became extinct, however, highlights the potential susceptibility or "cost" of having a warm-blooded metabolism, which necessitates a continual high food consumption.

In his words, "It's quite possible that there was a shift in the ecological landscape due to the climatic cooling that caused the seal level to drop, altering the ocean environments, where the populations of the types of food megalodon depended on, such as marine mammals, possibly became scarce, leading to the demise of megalodon."